HAWQ-169. remove useless variable found by coverity
HAWQ-169. remove useless variable found by coverity

lavjain/incubator-hawq,cwelton/incubator-hawq,cwelton/incubator-hawq,outofmem0ry/incubator-hawq,stanlyxiang/incubator-hawq,lavjain/incubator-hawq,outofmem0ry/incubator-hawq,huor/incubator-hawq,lavjain/incubator-hawq,huor/incubator-hawq,wengyanqing/incubator-hawq,cwelton/incubator-hawq,outofmem0ry/incubator-hawq,wengyanqing/incubator-hawq,cwelton/incubator-hawq,jianlirong/incubator-hawq,outofmem0ry/incubator-hawq,wengyanqing/incubator-hawq,jianlirong/incubator-hawq,huor/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,lavjain/incubator-hawq,stanlyxiang/incubator-hawq,cwelton/incubator-hawq,huor/incubator-hawq,huor/incubator-hawq,huor/incubator-hawq,jianlirong/incubator-hawq,wengyanqing/incubator-hawq,stanlyxiang/incubator-hawq,stanlyxiang/incubator-hawq,outofmem0ry/incubator-hawq,stanlyxiang/incubator-hawq,outofmem0ry/incubator-hawq,cwelton/incubator-hawq,wengyanqing/incubator-hawq,outofmem0ry/incubator-hawq,stanlyxiang/incubator-hawq,cwelton/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,wengyanqing/incubator-hawq,outofmem0ry/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,huor/incubator-hawq,wengyanqing/incubator-hawq,jianlirong/incubator-hawq,wengyanqing/incubator-hawq,jianlirong/incubator-hawq,lavjain/incubator-hawq,stanlyxiang/incubator-hawq